Forming, sterilizing, filling and sealing machines have incorporated various techniques heretofore to sterilize paperboard cartons for carrying non-carbonated or "still" liquids, such as juices. One such machine is shown and described in U.S. Pat. No. 3,566,575, wherein a hydrogen peroxide mixture is supplied via an integrally mounted fogging nozzle into the open tops of cartons being fed through the machine, and heated therein to remove the fog from the cartons just prior to being filled with the designated liquid.
Another forming, filling and sealing machine incorporating a sterilization section intermediate the bottom forming and sealing section and the filling and top forming and sealing section is shown and described in U. S. Pat. No. 4,566,251, wherein the sterilization section has a separate conveyor for carrying the cartons through the latter section, and subjecting them to a sterilant vapor at a temperature substantially higher than that of the cartons, causing the vapor to condense on all surfaces of the carton, and then turned upside down by the conveyor to allow any condensate to drain therefrom while being dried prior to being lowered in an upright position.
Insofar as closed loop systems are concerned, for use with a container filling machine through which the containers are conveyed, Sjostraud No. 4,055,035 discloses a method of extracting sterilized air and vapor from a web type packaging machine, passing it through a liquid ring compressor, and returning a purified air to the packaging machine where the web has been subjected to sterilant by an application roller.